To fabricate a large scale integrated circuit (LSI) semiconductor device, it is increasingly important to form a metal interconnect resistant to high current density that is caused by scaling of a semiconductor device. That is, as semiconductor devices are increasingly miniaturized, and much more transistors are integrated on a unit area, the sizes of metal lines connected to transistors are decreased, so that the density of currents flowing through the metal lines is increased.
As the density of currents is increased, breakage possibilities of metal interconnects may be increased. Particularly, breakage of metal interconnects may be caused by electromigration (EM). Thus, a metal interconnect having an improved structure resistant to breakage due to electromigration, and a method of fabricating the metal interconnect are required.